The present invention relates to conductive, low warp polyetherimide resin compositions.
Polyetherimide resin compositions have been used to fabricate parts for numerous applications. Each application requires particular tensile and flexural properties, impact strength, heat distortion temperature, and resistance to warp. For example, U.S. Pat. No. 4,455,410 provides a polyetherimide-polyphenylenesulfide blend having good flexural strength characteristics. U.S. Pat. No. 3,983,093 provides polyetherimide compositions having improved solvent resistance and suitable for use in preparing films, molding compounds, coatings, and the like.
When fabricating certain components, a combination of low warp and low surface resistance (i.e., high electrical conductivity) are required. The warp of a given product is dependent upon composition, the geometry of the product and processing conditions such as molding temperature and pressure.
For a material to be useful in computer chip tray applications, the material must provide low warp properties and must possess a surface resisitivity of less than about 106 ohms per square centimeter (ohms/cm2). This is difficult to achieve because the polyetherimide is non-conductive and high levels of conductive materials, such as carbon fiber, added to achieve the desired low surface resistance may contribute to an increase in warp.
There remains a need, therefore, for conductive polyethermide compositions having low warp and low surface resistance.
The present invention provides a polyetherimide composition having low warp and conductive properties prepared by combining a polyetherimide resin or polyetherimide-copolymer resin and a filler composition wherein the filler composition comprises a plate-like filler and a conductive filler.